Pensions Funded Status (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Defined Benefit Plan Disclosure [Line Items]
Cash contributions to retirement plans	$ 50	$ 93	$ 200
Minimum [Member]
Defined Benefit Plan Disclosure [Line Items]
Estimated Employer Contributions in Next Fiscal Year	40
Maximum [Member]
Defined Benefit Plan Disclosure [Line Items]
Estimated Employer Contributions in Next Fiscal Year	60
Pension Plans, Defined Benefit [Member] | United States
Change in Projected Benefit Obligation [Roll Forward]
Benefit Obligation at Beginning of Year	1,179	1,300
Business combinations/divestiture		8
Interest costs	45	41	43
Actuarial (gains) losses	156	(87)
Benefits paid	(78)	(83)
Benefit Obligation at End of Year	1,302	1,179	1,300
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair Value of Plan Assets at Beginning of Year	1,091	1,181
Business combinations/divestiture		7
Actual return on plan assets	183	(49)
Employer contribution	5	35
Benefits paid	(78)	(83)
Fair Value of Plan Assets at End of Year	1,201	1,091	1,181
Funded Status	(101)	(88)
Accumulated Benefit Obligation	1,302	1,179
Amounts Recognized in Balance Sheet [Abstract]
Current liability	(6)	(6)
Noncurrent liabilities	(95)	(82)
Net amount recognized	(101)	(88)
Amounts Recognized in Accumulated Other Comprehensive Loss [Abstract]
Net actuarial loss	195	168
Net amount recognized	$ 195	$ 168
Weighted Average Assumptions Used to Determine Benefit Obligation [Abstract]
Discount rate	3.12%	4.21%
Pension Plans, Defined Benefit [Member] | Foreign Plan [Member]
Change in Projected Benefit Obligation [Roll Forward]
Benefit Obligation at Beginning of Year	$ 1,193	$ 1,324
Divestiture	(23)
Service costs	23	26	26
Interest costs	24	23	21
Settlements	(34)	(33)
Plan participants' contributions	5	5
Actuarial (gains) losses	136	(48)
Benefits paid	(27)	(34)
Currency translation and other	6	(70)
Benefit Obligation at End of Year	1,303	1,193	1,324
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair Value of Plan Assets at Beginning of Year	932	1,011
Divestiture	(15)
Actual return on plan assets	60	(21)
Employer contribution	43	56
Settlements	(34)	(33)
Plan participants' contributions	5	5
Benefits paid	(27)	(34)
Currency translation and other	22	(52)
Fair Value of Plan Assets at End of Year	986	932	1,011
Funded Status	(317)	(261)
Accumulated Benefit Obligation	1,238	1,136
Amounts Recognized in Balance Sheet [Abstract]
Noncurrent assets	97	106
Current liability	(8)	(8)
Noncurrent liabilities	(406)	(359)
Net amount recognized	(317)	(261)
Amounts Recognized in Accumulated Other Comprehensive Loss [Abstract]
Net actuarial loss	200	106
Prior service credits	(3)	5
Net amount recognized	$ 197	$ 111
Weighted Average Assumptions Used to Determine Benefit Obligation [Abstract]
Discount rate	1.60%	2.34%
Average rate of increase in employee compensation	2.27%	2.47%
Postretirement Benefits [Member]
Change in Projected Benefit Obligation [Roll Forward]
Benefit Obligation at Beginning of Year	$ 50	$ 63
Business combinations/divestiture		1
Service costs	1	1
Interest costs	2	2
Actuarial (gains) losses	3	(8)
Benefits paid	(2)	(2)
Currency translation and other	1	(7)
Benefit Obligation at End of Year	55	50	63
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair Value of Plan Assets at Beginning of Year	8	9
Actual return on plan assets	2	(1)
Employer contribution	2	2
Benefits paid	(2)	(2)
Fair Value of Plan Assets at End of Year	10	8	$ 9
Funded Status	(45)	(42)
Amounts Recognized in Balance Sheet [Abstract]
Noncurrent assets	9	8
Current liability	(3)	(3)
Noncurrent liabilities	(51)	(47)
Net amount recognized	(45)	(42)
Amounts Recognized in Accumulated Other Comprehensive Loss [Abstract]
Net actuarial loss	5	4
Prior service credits	(5)	(5)
Net amount recognized	$ 0	$ (1)
Weighted Average Assumptions Used to Determine Benefit Obligation [Abstract]
Discount rate	2.86%	3.81%
Initial healthcare cost trend rate	5.98%	6.35%
Ultimate healthcare cost trend rate	4.48%	4.89%
Postretirement Benefits [Member] | Minimum [Member]
Weighted Average Assumptions Used to Determine Benefit Obligation [Abstract]
Year that Healthcare Cost Rate Reaches Ultimate Trend Rate	2020
Postretirement Benefits [Member] | Maximum [Member]
Weighted Average Assumptions Used to Determine Benefit Obligation [Abstract]
Year that Healthcare Cost Rate Reaches Ultimate Trend Rate	2040